RegEx tool was the essential component in this workflow.
However, it seems that depending on the pattern specification, the results may be different!
While "\w+" and "\<\w+\>" result the same as the solution demonstrates, the specification "[[:alpha]]+" and "[a-zA-Z]+" will provide different results, as the digits will be excluded. The suggested solution "\<\w+\>" would potentially even recognize 0, 00, 003 etc. as word. Thus this approach may blow off the true number of total words.
It would be really interesting to know, if there's further clarification why the solution has used "\<\w+\>" rather than "[[:alpha]]+" or "[a-zA-Z]+" as pattern.
I have learned something new from this case. First is a new RegularExpression '\w+' which could eliminate space, tab and all punctuations. The second one is 'Download' tool from Developer tab which is useful when I have to get dynamic data from website. Great learn!